Adjustable shelving units employing shelves constructed of sheet metal or wire are well known and extensively utilized, and such shelving units are normally referred to as knock-down shelving since they are intended to be readily assembled and disassembled. For this purpose, the shelving unit normally utilizes a corner structure for securing the shelves to upright posts. In situations where strength and rigidity of the assembled shelving unit is of significance, the corner structure generally employs a sleeve or collar arrangement which totally surrounds the corner post to achieve a secure and rigid clamping engagement with the post to prevent what is commonly referred to as "racking". Such corner structure, however, not only makes assembly of the shelving unit more complex since the sleeve or collar must be slidably inserted over the post from one end, but this corner structure also makes partial disassembly or rearrangement of the shelves more difficult. For example, with most known shelving units employing a corner structure of this type, the corner structure does not permit a bottom or intermediate shelf (that is, a shelf located between upper and lower shelves) to be mounted on or removed from the post after the shelving unit has been assembled due to the inability to position a corner structure in surrounding relationship to the post.
A known shelving unit of the above type which has achieved significant commercial success provides a sleevelike corner structure which telescopes downwardly over the post, and a conical clamping sleeve which is normally diametrically split into two pieces and is wedgingly interposed between the collar and post. This arrangement, wherein the intermediate conical clamping sleeve is utilized, has proven desirable inasmuch as this positively ensures a positive wedging and hence secure engagement of the shelf with respect to the post so as to provide an extremely strong connection which hence tends to minimize looseness or "racking". The shelving units employing this intermediate conical sleeve, however, have still normally possessed features which have been considered undesirable with respect to the required assembly and disassembly techniques, the inability to add or remove intermediate shelves, and the general overall structural and functional complexities associated with some of the collar structures.
Accordingly, it is an object of this invention to provide an improved adjustable shelving unit, specifically a metal shelving unit, having an improved corner structure coacting between the shelves and the corner posts, which corner structure permits and retains the utilization of a intermediate conical clamping sleeve interposed between the post and the corner collar, but at the same time this improved corner structure overcomes many of the disadvantages associated with prior shelving units of this general type. More specifically, the improved corner structure of this invention facilitates the assembly and disassembly of the shelves, including the assembly or disassembly of an intermediate shelf with respect to an assembled shelving unit, and permits the corner structure to be efficiently and economically fabricated while at the same time providing not only greatly increased flexibility but also providing a compact corner structure having a desirable appearance when assembled into the shelving unit.
More specifically, this invention relates to an improved corner structure, as aforesaid, which is formed basically by three one-piece members. The first member comprises a plastic sleeve having an external conical configuration, the sleeve being axially split throughout the length thereof to facilitate its elastic spreading so that it can be moved transversely into surrounding gripping engagement with the post. The second member involves a channel-like corner piece which is preferably welded directly to the shelf adjacent a corner thereof, this corner piece defining an arcuate channel which permits it to snugly embrace one side of the plastic sleeve. The third member comprises a strap which also has a channel adapted to embrace an opposite side of the plastic sleeve, the strap and corner piece having cooperating wedge structures which lockingly join the strap and corner piece together so as to effectively define a closed collar having an internal conical bore which is maintained in snug clamping engagement with the exterior conical surface of the plastic sleeve. The second and third members are held together solely by the wedged relationship created therebetween, which relationship involves a pair of flangelike wedges on opposite sides of the strap, and a pair of wedgelike slots formed on opposite sides of the corner piece for individually receiving therein the flanges of the strap.
In the improved corner structure of this invention, as briefly described above, the three members cooperate with one another and with the post in such manner as to result in minimum cracks or crevices so as to permit utilization of the unit in environments requiring sanitary conditions. At the same time, the corner structure permits the shelf to be assembled onto or removed from the post in an easy and simple manner without requiring any special or complex tools, and without requiring the use of additional fasteners such as screws or the like, and which permits the complete corner structure to be engaged on or removed from the post wholly by moving all of the three members in a transverse direction with respect to the longitudinal axis of the post, whereby assembly or disassembly can be totally accomplished without requiring any of the parts to be telescoped over the length of the post. At the same time, the resulting corner structure, when assembled on the post, provides an extremely secure and tight clamping and supporting engagement of the shelf relative to the post.
Other objects and purposes of the invention will be apparent to persons familiar with structures of this general type upon reading the following specification and inspecting the accompanying drawings.